Provided is a puncturing instrument capable of administering (supplying) a liquid drug. The puncturing instrument comprises: a puncturing tip (2); a first tubular body (3) connected to the puncturing tip (2) at the distal end thereof; and an outside tubular body (5) covering at least part of the first tubular body (3). The first tubular body (3) is formed so as to be rotatable around a shaft in the longitudinal direction. The outer diameter of the first tubular body (3) is smaller than the inner diameter of the outside tubular body (5) and a liquid drug supply path (5a) is provided on the outside of the first tubular body (3).